Re: Scalability requirements for sysv ipc

[Mike Galbraith <efault@gmx.de>]

On Fri, 2008-03-21 at 17:08 +0100, Manfred Spraul wrote: 
> Paul E. McKenney wrote:
> > I could give it a spin -- though I would need to be pointed to the
> > patch and the test.
> >
> >   
> I'd just compare a recent kernel with something older, pre Fri Oct 19 
> 11:53:44 2007
> 
> Then download ctxbench, run one instance on each core, bound with taskset.
> http://www.tmr.com/%7Epublic/source/
> (I don't juse ctxbench myself, if it doesn't work then I could post my 
> own app. It would be i386 only with RDTSCs inside)

(test gizmos are always welcome)

Results for Q6600 box don't look particularly wonderful.

taskset -c 3 ./ctx -s 

2.6.24.3
3766962 itterations in 9.999845 seconds = 376734/sec

2.6.22.18-cfs-v24.1
4375920 itterations in 10.006199 seconds = 437330/sec

for i in 0 1 2 3; do taskset -c $i ./ctx -s& done

2.6.22.18-cfs-v24.1
4355784 itterations in 10.005670 seconds = 435361/sec
4396033 itterations in 10.005686 seconds = 439384/sec
4390027 itterations in 10.006511 seconds = 438739/sec
4383906 itterations in 10.006834 seconds = 438128/sec

2.6.24.3
1269937 itterations in 9.999757 seconds = 127006/sec
1266723 itterations in 9.999663 seconds = 126685/sec
1267293 itterations in 9.999348 seconds = 126742/sec
1265793 itterations in 9.999766 seconds = 126592/sec

	-Mike